Use of time-lapse photography equipment for hydrologic studies

This report describes equipment used for recording hydrologic events photographically on a controlled time scale. Equipment used included a 16-mm (millimeter) motion-picture camera, batteries, and associated intervalometer hardware.

Variables that affected operation of the equipment, and which were used to turn the equipment on and off upon demand, were sunlight intensity, rainfall, and time. Winding of the camera and final shutdown were accomplished manually.

A 15-minute silent motion picture was made from the time-lapse film installed at Bolinas Lagoon. This film shows sand erosion and deposition on the Stinson Beach Spit during the period January 1968 to July 1969.